A Lesson In Biology
by Wendy McCalister
Summary: Botan pays Kurama a visit after being away for work for two months... only to find out her sexy and foxy demon boyfriend has a 'unique' way of teaching Biology. Pure KxB smut.


**A Lesson In Biology**

 **Disclaimer: I do not own Yu Yu Hakusho.**

 **Summary: Botan pays Kurama a visit after being away for work for two months… only to find out her sexy and foxy demon boyfriend has a 'unique' way of teaching Biology. Pure KxB smut.**

Botan knocked on the glassy surface, watching as Kurama stood up from his spinning chair and walked over to open the window for her. She flew through it and jumped off her oar, the wooden item disappearing as she landed on the floor of Kurama's bedroom with a thud.

Her mouth curving into a smile, Botan couldn't help but scrutinize his appearance. He was wearing a simple white buttoned down shirt, along with a pair of blue jeans and spectacles at the bridge of his nose. She noticed his long red hair was also slightly messy, making him looked as if he hadn't got enough sleep from last night. He was still handsome in her eyes though, as always.

Kurama smiled lazily back at her, before sauntering away to sit at his chair once again. Botan raised an eyebrow at him in question, her amethyst eyes filling with worry as she took notice of the slight difference in his behavior. Usually, he'd give her a hug or a kiss, but today he didn't seem in the mood for neither of those things.

She walked to him and took a sit on his desk, careful enough not to sit on the papers and books lying there. "What's wrong? You don't seem like yourself?" she asked in concern, her blue brows furrowing.

Kurama heaved a heavy sigh. "Sorry, sweetheart. It's just… lately, there have been a lot of missions for the boys and I to deal with," Botan nodded as he went on, "and my exams are around the corner and I've only got time to study last night. I haven't slept, and I'm getting quite stressful…" he mumbled, running a hand through his crimson tresses. "Sorry again," he apologized for some reason, "You've just come visit me and I haven't seen you for months, yet I'm not giving you any attention."

"Don't worry about it," Botan responded with a smile, bending down slightly to give him a small peck on his right cheek. She pulled away, her smile considerably widening. "I understand you're busy. It's fine, I don't mind. I was just getting worried, I thought you got bored of me or something… though I did notice you look exhausted."

A deep frown came to rest on the demon fox's forehead. "Got bored of you? Oh, sweetheart," and then, he pulled her gently towards him, bringing her down to his lap, "I'll never tire of you for the rest of my life," he whispered softly and looked deep into her eyes.

"I know," she replied knowingly, before moving to get up from him. "I didn't mean to disturb you, Kurama. I'll go visit Yusuke and the others first, then I'll come back tomorrow, 'kay? Seems like you've got a lot to handle right now," she told him, sparing a glance at the papers on the desk.

As much as she wanted to be with him right now… especially after not seeing him for such a long time… she didn't want to bother him. She knew how much school matters mattered to Kurama, and knowing that she still had another day (since Koenma was generous enough to give her two days off to spend time with her friends), she could visit him anytime. Except now maybe wasn't the right time.

Botan turned around, materializing her oar in her hand and trying not to look or feel disappointed. She was about to jump on when a hand suddenly grabbed her wrist, pulling her down. Caught off guard, she accidentally made the oar disappear. The next thing she knew, she was on Kurama's lap once again.

"Kurama…"

"Don't go," he said in a low voice, soft and pleading as he laid kisses on her pearl white neck. She moaned at the feel of his warm lips, causing him to smirk against her skin.

"But…" She tried to get up again, however it was to no avail, as Kurama's hands were on her hips, keeping her still and on him. "I don't want to be a nuisance—"

"You're not," he cut her off, his voice stern yet gentle at the same time. She had a doubtful look on her face, so he gave her a reassuring smile to try to convince her. "I have biology tomorrow, and I've studied for it last night, so don't even think about that. I can stop my studies right now, if you want to."

"Really?" She sounded half hopeful and half doubtful as she asked this.

"Really," he confirmed. "Would you mind getting off of me for a sec though?" he added with humor, mirth dancing in his piercing emerald orbs.

The corners of Botan's mouth pulled up into a bright, jovial smile as she nodded happily at his response. "You're the one who pulled me though," she retorted back with a laugh, before getting up from his comfortable lap.

He gave her a playful smack in the ass, making her squeal in pleasant surprise. She laughed again as Kurama placed a hand to his lips, a chuckle escaping him. She watched for a moment as he closed his biology papers and started to arrange his papers neatly. Her eyes focused on one particular paper about bones in the human body, before Kurama grabbed it and joined it with the rest.

He turned around, noticing the curious look in her eyes and her gaze still on his desk, where the paper once laid. Raising an eyebrow at this, he asked, "What is it?"

"Eh?" she asked back, dumbfounded for a moment. Then, as if she just realized he just inquired at her, her mouth formed an 'o'. She let out a sheepish laugh and scratched the back of her not so scratchy head. "I-it's nothing," she stuttered… which meant something.

"Really? It doesn't look like nothing to me," Kurama told her, his mouth stretching into an amused smile as a blush appeared on his girlfriend's face.

"I-it's just… I was just curious about… er, biology," she answered finally, keeping her eyes glued to the floor as she fidgeted now and then.

"Biology?" He arched an eyebrow at her once again, half amused and bewildered by her words.

"Yeah… I mean, you know I've been a human before, right? Before I became a ferry girl…" She waited for him to nod his head, which he did, "… and, well, I used to fail at my biology tests at school in my previous life and I-I don't know, I just feel like I want to… um, master it? For some reason."

Her ears grew hotter at each sentence, and her face grew redder as each word passed her lips. It was stupid. Kurama had just agreed to spend a fun time together, and she just had to bring up school subjects. As if he wasn't stressed enough. And as if it mattered anymore. She was a ferry girl now, and it wasn't like she was going to take exams for biology or something again.

She wasn't aware that an idea just flashed in Kurama's head.

Botan was about to tell him that he should just pretend what she just said didn't happen, but then, he took the biology textbook in his hands and strangely enough, said, "Is that so? If it is, I wouldn't mind teaching you a few things. I'm pretty damn good at it," A proud grin found its way to his charming features, before he stood up from the chair and held a hand towards it, gesturing at her to sit. "Come here, sweetheart. Let's get our lessons started."

"A-are you serious?" she asked with a weird look on her face. She was about to walk to the bed instead of the chair, but halted in her tracks the second Kurama sent her a stern look, silently ordering her to do as she was bidden. She sighed, knowing now that he _was_ serious and did as she was told to, her butt flopping to the soft cushion on the chair.

"You don't have to do this, you know," Botan muttered under her breath, as Kurama moved an inch closer towards her until she could feel his hot breath on her ear.

She shivered in delight as he whispered seductively into her ear, "I thought you wanted to know?" and she could've sworn he was up to something naughty. Not that she minded it though, but it was scary that she didn't know what it was.

He pulled back, this time sauntering beside her and lightly leaning against the desk. He opened the biology book and flipped through the pages to find something good to teach her about. He stopped at one, the corners of his mouth curving upwards into a grin.

"This seems like a good place to start."

About an hour passed since then, and Botan lightly banged her head against the desk. A sigh, low yet pleased, escaped through her pink lips. "That was a good lesson!" she stated happily, before lifting her head up and stretching her arms.

Kurama was a great teacher. He knew just the way to make her understand the things she never did, and he thought her a lot of things she didn't think she knew before. It was actually fun learning with him, and she felt as if she got a gist of what it felt like to be a student once. For a moment there though, she thought he was going to do something to her, but he didn't. Maybe Kurama up to 'no good' was just her imagination?

He was about to prove her wrong.

"Let's have a quiz," he spoke all of a sudden, sounding calm, despite the mischievous idea going through his head.

Botan looked up to peer at him with an arched eyebrow. "A quiz?" she repeated, blinking once, her face contorted in nothing but confusion.

"Yes," he confirmed, moving from the desk and walking to the bed. Botan's eyes followed his every movement, curious as to what he was about to next. Then, he turned to look at her, his mouth pulled up in a mischievous smile as he held a hand out towards the bed. "Lie down."

"Lie down?" She was getting even more befuddled. "I thought this was quiz? Why do I have to lie down?"

"No questions. A student shouldn't be talking back at the teacher," he purred, his tongue darting out to lick his lips. His eyes trailed up and down her body, before going back to her face, making a shiver run down Botan's spine and a familiar feeling appearing between her legs. "Now be a good student and lie down for me, okay?"

She nodded her head slowly. "O-okay," she stammered, walking towards the bed with slightly trembling legs.

Now _that_ just now wasn't just her imagination.

He was literally checking her out.

Even now, she could feel his eyes glued on hers, watching her every movement as she lied down on the bed, her head touching his soft blue pillow. She waited for his next command, which came immediately, "Take off your clothes."

This time, his voice sounded predatory.

She gulped in her throat, sitting up from the bed to take off her pink tank top, before throwing it beside the bed. It felled to the floor, followed by Botan's blue denim shorts.

Botan could feel his eyes staring at her hungrily even if she wasn't looking at him. Right now, she was only mild naked, with her innerwear being the only things she hadn't taken off. Her bra and panties needed to go to, she knew that already, and reached a trembling hand to her underwear. Lifting her hips, she pulled it down and joined it with her other articles of clothing on the floor. She reached behind her, unhooking her bra and was about to throw that away too, only to stop when Kurama spoke, in a now low and husky voice,

"Leave that on the bed."

She turned to give him a questioning gaze, but the look faltered quickly as she noticed the once bright emerald eyes now clouded with lust and turned into a darker shade of forest green. She did as he said, lying the bra next to her and watched with equally lustful eyes as he started taking off _his_ clothes.

Seconds ticked by, before he was only in his boxers. She eyed the bulge in them for a moment, unconsciously licking her lips at the thought of touching it. But she needed to see it first, so she lifted her eyes to his, pleading him to take them off.

However, instead of doing what she silently asked, he gave her a wolfish grin and merely crawled onto the bed. Before she knew it, he was already on top of her, looming over her with that grin on his face widening slightly. She was about to ask him what he was smiling about, but didn't manage to as she suddenly felt her arms being pulled up and something biting into her wrists.

 _Hard_.

She looked up instantly to see what it was, moaning loudly.

It was her bra.

Kurama had just tied her up with her own bra.

She tugged at it, testing how tight it was around her wrists. It was firm, and the minute she tugged, it hurt.

God, it must be really tight.

She couldn't get out of it.

Kurama could do whatever he wanted with her. For as long as he wanted.

Just thinking about him murmuring dirty words into her ear, his hands roaming all over her sensitive skin, and her being unable to touch him back and unable to move made her soaking wet.

Things couldn't get hotter than that.

Botan could feel her underwear getting damper, and pressed her legs together to try to ease the ache between her thighs. Kurama, however, wasn't about to have any of that, and in one swift movement, yanked her legs apart, one hand sliding along her inner thigh. But he remained a tease, not even touching her where she wanted him to.

"What are you doing, Kurama?" she whispered, voice hoarse and desperate.

"I told you, I'm about to give you a quiz," he told her calmly, as if he didn't just tell her to strip down and tied her up to the headboard. Looking all poised as he continued, "I'm going to ask you questions, and if you answer them right, I'll reward you with each correct answer." His hands slide up her legs, up her sides, before stopping just beneath her breasts.

"I'll give you an easy start." Kurama straddled her, making sure not to press his still clothed erection against her heat. "How many bones are there in the human body, Botan?"

That was easy. She could answer that in an instant. And she did. "206," she responded immediately.

Kurama's hands trailed up her chest, squeezing her breasts and teasing her rosy buds with the pads of his thumbs. "Very good, love," he told her with a chuckle, grinning seductively as he earned a moan from his girlfriend.

"N-next question," Botan panted out, loving the way he twisted and pinched her sensitive nipples. He grinded his hips against hers, making her let out a startled gasp. She quickly bit her lip to suppress a moan, but grinded back, rubbing up and down and pressing against the bulge in her boyfriend's pants.

His mouth crushed hers hungrily, his tongue grazing over her lower lip for permission, which she quickly granted, opening her mouth. Their tongues battled for dominance, which was won easily by Kurama. Their teeth bumped against each other for a second, and he moaned into the kiss, grinding harder against her, "How many baby teeth do humans have?"

He broke off the kiss to hear her answer, much to Botan's disappointment.

"T-twenty," she sputtered.

One of Kurama's hands instantly traveled down her stomach. Lower, lower and lower… until it finally brushed against her entrance. He rubbed his fingers up and down her folds in a slow pace, torturing her. A few moments passed, then he finally, finally slid two fingers into her, and Botan nearly sobbed with relief. But his pace remained the same as before.

"You're soaked," Kurama growled, eyes on hers as her mouth hung open and her eyes shut tight in frustration. There was a hint of longing in his voice, as he started talking dirty, "I could eat that tight pussy for hours on end, sweetheart," but he still slid his fingers in and out of her agonizingly slow, and Botan pushed her hips up, telling him to go faster, deeper, and harder. Because it wasn't enough, not nearly enough after how long she had waited for this.

"Then just do it already!" she nearly screamed, as she squirmed under him, twisting her wrists around but still unable to loosen the restraints. She had always loved that black lacy bra of hers; it was her favorite. But now, for once in her life, she actually hated it. Now that it was keeping her from touching Kurama and showing the fox demon just how rough she liked it.

A low chuckle escaped him, half amused at her impatience. "Maybe not," he told her, licking his lips once again at the delicious sight of her writhing beneath him. "We're still not finished," and he plunged slightly deeper into her, causing her to gasp in pleasure. A smirk found its way to his face, his eyes glinting gold for a moment before reverting back to their original green. "Lactose intolerance is a frequent reason to avoid milk and dairy products. Can you tell me what lactose is, love?"

"A-a sugar," She felt him curl his fingers in her, and hissed in pleasure, "Oh, my god."

"Keep going," he spoke calmly, but she could tell there was suppressed lust lying dormant in that smooth voice of his, "What sugar?"

"Ah… Mmm, it's a disaccharide sugar… Oh, _oh_ … that makes up around 2-8 percent of milk. L-lactose isn't an allergy, it's the – _Ah, yes_ – Mmm, it's the inability to digest lactose… due to… insufficient levels of lactase…" she answered between breathy gasps, moans and whimpers of pure pleasure as he quickened his pace, going deeper and deeper inside her.

"And what is lactase?"

"I-it's the enzyme that metabolizes lactose into glucose and galactose," she responded in a quick sentence, bucking her hips rhythmically with his fingers. Her movements were clumsy, but it successfully gave her more pleasure. More… she wanted – no, needed – more.

Kurama groaned in response, getting even more turned on by how wild she rode his fingers. "God, you don't know how much I want to fuck you right now," he growled, sliding in another finger inside her and thrusting the three fingers faster, her moans getting louder in the room as he did so. "Keep going and going until you were crying and completely wrecked, until you couldn't even remember you own name and you were just screaming mind over and over again, because you can't think of anything other than me and how good my cock makes you feel."

Botan let out a loud moan at his words. Hearing him say it made her wetter, coating his fingers with her juices as he plunged in and out of her. He rarely cussed, but it made him sexier and aroused her even more.

"Then why don't you?" she responded back between breathy pants.

He smiled, able to tell she couldn't hold out much longer. He could feel his control slipping in mere moments, too, but he wanted to ask her one last time before he could finally give them what they both wanted. Wanting to tease her again. "Final question," he purred, chuckling at the exasperated groan he earned from her. He pulled his fingers out of her, and Botan whined at the feeling of lost she got in return.

"Look at me," he ordered, voice firm yet husky as he spoke. She did, biting back a moan at how lustful he was looking at her. She watched as he yanked his boxers down, throwing it from his shoulders, not caring where it landed and her eyes immediately felled to his shaft. Seven and a half inches. Big. It was _big_. The thought of _that_ entering her and fucking her senseless nearly made her orgasm right then and there. She was barely hanging on as it is, but he decided to tease her even further, rubbing himself up and down, his cock twitching in his hand as she groaned and threw her head back.

Kurama smirked at her reaction, satisfied, before brushing the tip of his cock against Botan's clit. Botan's hips jerked involuntarily in response, trying to get him to go deeper, and yet he didn't, merely rubbing between her folds. She wanted to tell him to just _fuck her already_ but held back at the reminder that there was one last question.

"Y-your question?" she asked, panting hard.

"Y-yeah," he panted back, his chest rising up and down in quick, aroused breath, "What's the largest muscle in the human body?"

Botan bit her lip, shutting her eyes in concentration. Or at least, she was trying to concentrate. She could just feel it, she could feel the answer at the tip of her tongue. It was something she was supposed to know already, but she couldn't quite focus as Kurama continued to tease her dripping cunt.

"I- I don't know… I can't think!" she cried out, tears forming at the back of her eyes.

"Can't think of anything besides me fucking you, Botan? Stretching you with my cock until you come again and again?"

"Yes! Oh yes, yes… just take me already, Kurama. I can't keep up with your stupid games anymore, I don't care anymore, just—just fuck me already!" Botan screamed, dropping the F bomb for once in her lifetime, her voice so loud she could've sworn the neighbors could hear them. Probably even Shiori downstairs. But she didn't care, she needed him. And she needed him, _now_.

That was all the motivation Kurama needed, and he buried himself deep into her, until his balls was touching her skin, her slick core enveloping him immediately. He started to move, his thrusts slow but deep. Botan mewled at the sensation – oh god, how she missed this. She threw her head back, wanting nothing more than for him to move faster into her, for him to pound into her until she bruised and forgot how to walk. She arched her back, desperate for him to go faster.

Kurama complied, ramming into her, hard, slamming his hips against hers so quickly Botan's mind went blank. The sound of skin slapping skin reverberated the walls, moans and whimpers falling from Botan's lips as Kurama groaned and panted. _KuramaKuramaKurama_ —she repeated over and over again with each breathy pant, saying his name again and again like a prayer.

All of a sudden, Kurama stopped and Botan was about to curse at him, thinking this was another one of his attempts to give her more torturous teasing. But then, he lifted her legs and wrapped them around his shoulders, making him go deeper into her and causing her to let out a gasp of pleasure.

Oh. _Oh_.

He didn't waste anymore time, didn't even hold back as he thrusted into her faster and deeper than before. Botan's back rubbed up and down against the bed again and again with each thrust, pleasure rocketing through her body. Kurama's hands grabbed her hips, squeezing the two mounds, as if motioning her to move. She got the message and instantly did, bucking her hips wildly against his thrusts, giving both of them more pleasure.

Kurama growled in response, slamming into her as hard and fast as he could. Botan shut her eyes tight, panting hard at each powerful thrust of his hips as he hit that sweet spot inside her, pleasure entering every cell in her body.

"Botan, Botan…" he called between pants, "Look at me," That same order came again, and she swiftly opened her eyes, looking downwards to look at him in the eye.

"Can anyone fuck you like this?" he snarled, thrusting into her ferociously. "Can anyone make you feel like this?"

"No!" Botan cried out, aroused by his dirty talk and clamping down hard on his penis, not wanting him to stop and wanting to come so hard. "Only you can!" The coil in her tightened; she needed release. Oh god, she was so close—so, so close.

Kurama growled in appreciation at the answer, obviously pleased, and then, impossibly, increased his speed once more. Flesh slapped flesh and Botan found herself screaming in pleasure. "Ah! Yes, yes! That's it! Yes, yes, oh god, yes!"

The fox heard a call from downstairs, "Shuichi?" and in one swift movement, covered Botan's mouth with his, silencing her screams. And she could tell he was close too, his thrust becoming more erratic and sloppy, his kiss all tongue and no technique.

"Yes, yes, yes…" she said again and again in the kiss. Gasping and moaning as Kurama rammed into her with brute force. She could feel every inch of him, thrusting into her again and again; every inch of his huge cock sliding into her battered pussy with inhuman speed. "Kurama… I-I'm gonna… I'm coming—"

 _Oh fuck._

Botan arched her back, screaming into the kiss as her orgasm overrode her senses and breaking off the kiss to bite onto her lip, so hard that it bled.

It took her a moment, but then she realized Kurama was still thrusting into her, now focusing on his own orgasm. She watched him; eyebrows creased in frustration and teeth gritted against each other. A few more hard, deep thrusts followed, before he came, his juices shooting out in long spurts inside her.

He yanked himself out of her, her legs sliding off of his shoulders as he groaned at the lost of warmth, while Botan moaned loudly, loving the feel of his cum dripping down her clit and thighs.

"I love you," he confessed lovingly, breathy and laid his forehead against hers as he tried to catch his breath.

Botan nodded her head, panting harder than he was. "I love you too."

He noticed the blood dripping down her chin and quickly darted his tongue to swipe it away, plunging it into her mouth. She took this as an advantage and sucked hard on the wet appendage, loving the throaty moan she earned in returned.

He pulled back, looking down at her intently. "You should stop that. I just might keep you to myself, and you won't be able to see Yusuke and the others for the rest of the day."

She let out a giggle, wrapping her legs around his waist, and smirking at his groan. "Who knows? I might like that," she teased, rubbing up and down his shaft, which twitched and immediately became hard again.

Kurama didn't say anything in response, and merely got up from the bed, ignoring the frown on Botan's face as he did so. Her eyes followed his every movement as he slowly—

Her amethyst orbs widened.

Why the _hell_ was he _putting on his clothes_?

She wondered for a moment if this was actually happening. But then, she saw him buttoning his shirt, and heard a zipping sound, confirming that it was.

"You wouldn't dare," she warned, narrowing her eyes at him.

Kurama turned to look at her with a devilish smirk. "Oh, but I would, love," and with that, he started to walk towards the door.

Leaving her.

"Wait!" Botan instantly called out frantically as his hand touched the doorknob.

He raised an eyebrow at her, feigning innocent as he tilted his head.

Her mouth formed a pout. "You're not leaving me, are you? You can't do that! N-not while I'm still tied up like this!" she went on, tugging hard at the bra which still acted as her restraints.

"No, of course I'm not," he replied, a huge grin appearing on his face, exposing his sharp incisors as he opened the door, his actions totally the exact opposite of his words. "I just remembered my mother asked me to go buy some groceries, so I'm going to do that."

"Y-you can't be serious, right?"

"Botan sweetheart, you know how important my mother is, right?" he asked back, taunting her by widening his grin. "You should be aware by now that her orders come first. I'll get back to you in a sec. I mean, we _do_ have more 'lessons' after this."

Botan opened her mouth to say something, but his words stopped her in mid-sentence,

"Of course, we'll do that when I get back from grocery shopping."

And with those final words, and a dark, amused chuckle, he closed the door. Leaving a blinking Botan, tied to his headboard with her lacy black bra, completely naked and utterly confused.

He just left her.

He actually left her.

"Kurama!" she groaned.

Damn that foxy tease.

Never mind, she'll get him next time.


End file.
